Monster(EDITED)
by Revlis Charm
Summary: [set after the Kyoto Arc] What if Satan had taken more interest in making Rin his vessel in Assiah, made him see horrible nightmares? What if he had tried to make Rin realize, that he is a real monster made to kill people? T for language, slight gore and violence. (Edited by RevlisCharm, all content belongs to original owner)
1. Chapter 1

Rin Okumura was laying on the bed, covered by a rather thick duvet and with his legs tangled in the sheets. Cold sweat was trickling down his forehead, which was making him shiver a bit. Something was odd. Really odd. He felt like he was about to burn from the heat of his own body.

He began to lose his consciousness gradually. His vision had become hazy, just a while ago, just as his mind's gone blank. Then he saw something more unrealistic. Everything before his eyes was covered, was burning more specifically due to blue flames. Suddenly, someone appeared in the vision. Black bangs covering his face and small flames, dancing vigorously on them. As he'd realized later, the man was no-one other than himself.

"Nii-san?" He heard a whisper, and felt the arm of his brother, shaking his shoulder. He regained his consciousness and looked at his twin brother a bit disoriented.

"Yuki…o.." He whispered even more quietly, grasping his hand tightly. The younger brother was a bit scared of Rin's actions, so he stepped back a bit just to escape from his brother's hold.

"What's up with you?" He asked, quite disoriented. Rin shook his head and slapped both his cheeks to get himself awake.

"Nothing…just a nightmare, I think…" He answered, getting up and walking past Yukio. He went outside without a word. Rin headed to the washbasin, so as to get rid of the sticky sweat that he had been covered in. He turned on the tap and accumulated a portion of water and splashed his face.

"Rin." A girl's voice came to his ears. It was Izumo. He turned around and greeted her with a big stupidly looking smile.

"What're you doing here this late?" He asked her, and waited for her response with a smile.

"I had had to bring my essay about the healing plants for Okumura-sensei." She replied, tangling her arms near her breast.

"What the heck?!" He screamed out of the blue, "We have to write an essay?! Yukio will definitely kill me." He groaned, seriously scared. Kamiki burst into laughter, just by looking at his actions. He had fallen to the floor and tightened his fists, when he was screaming.

"And today's the deadline." She added, after getting through his screams.

"You've got to be kidding me…!"

Miraculously, he had avoided his twin's anger. Everything had returned to normal. Rin had already forgotten about the nightmare that night. He was just as cheerful as he always used to be.

There was a small thing, that had been distracting him ever since the mission to Kyoto. It was his brother, that seemed to be really cold to him since then. He didn't know the reason behind the indifferent actions of Yukio towards him.

His thoughts were interrupted by his twin, talking to him.

"Don't think that I've forgotten about the essay. I'll give you two days. After the time I want to see it on my desk, understand." Said Yukio as coldly as he could, without looking at Rin.

"Roger!" exclaimed Rin, sticking two fingers to his right-upper side of forehead, so as to salute. He also made a funny face, sticking his tongue out a bit.

Yukio left without saying anything, heading up to the dormitory's exit. Rin did the same thing and as he left the huge building, he saw Shiemi sitting with Izumo and Paku on a small blanket in the yard. They were eating their lunch.

As he saw the short, blond-haired girl, he went up with an idea and happily ran to them.

"Shiemi!" He shouted, giving the girl goose bumps from the shock. She immediately turned her head and smiled as she recognized him. Shiemi waited for him, waving her hand happily.

"Rin!"

"Shiemi. Can you do me a favor?" He asked right after he arrived there. "Can you help me with an essay about the herbs?" He asked her for help, folding his hands like for a prayer. The girl smiled once again and nodded.

"Of course. We can even start now!" She replied cheerfully, standing up and waving to the other girls, who were still eating their bentos.

"That one's aloe!" She told him, pointing at a plant with a long stem, with a big, long flower at the end of the stem. "It's used for burns and juice from the leafs is used for poisoning." She explained with a serious look. Rin wrote a small note on the piece of paper, that was laying on the desk. They were in Shiemi's mother's shop. Surrounded by the glass-cases with various medicaments. Rin gazed out a bit. Yukio came to his mind…

"And that one's horsetail!" She said with excitement and looked at the boy. But he was really spaced out.

"Rin?"

The half-demon blinked. "Sorry…!" He apologized, and smiled neatly. "I was just thinking about something."

Rin returned after two hours with a complete essay. He left it on the desk, as Yukio had wanted.

As he had nothing to do anymore, he jumped onto the bed and rolled countless times. He closed his eyes and tried to sleep. As he closed them Rin saw the nightmare, that was similar to the first one, but there was something different.

 _There was him, staying alone in a yard. It was raining heavily, water pouring down from above. The black clouds had completely covered the sky, making everything darker. Then he saw a man, taller than him, dressed in a black coat sith buttons lining down. He didn't see his face, because it wasn't lifted._

 _"Just look at yourself." Said the man as he headed towards him. Rin's body was shivering. Suddenly, he realized, that his hands and his whole body was covered in bright blue flames. As he looked at the ground he saw someone burning, covered in flames. He stepped back shivering, looking again around the place._

 _"Wh-aa-at…?-" He stammered, releasing a small exclaim. He looked once again at the stranger. The man raised his head. It was Yukio…_

 _"You're just a monster, Nii-san." Hissed the younger one, with an indifferent voice and coldly pushed Rin away, when he grasped his coat. "A killing machine." he added at the end._

 _Shock grasped Rin's freezing body as he heard his brother's words. "Wh..what.." He choked out, his mouth dry suddenly. The younger twin glared at him._

 _"Don't you get it?!" Yukio exclaimed, hate seeping from his voice. He shoved the half-demon, and Rin looked at him in disbelief. "Your a fucking monster! Just get away from me!"_

Rin woke up, covered in perspiration, looking around as he slowly regained consciousness. Yukio was standing right before him, looking at his brother strangely. A small tear trickled down his cheek. Yukio noticed it unfortunately and grasped his hand.

"Don't touch me." Rin said coldly, his voice shaking as he moved back against the wall.

"Rin.." He once again grasped his hand and pulled him nearer.

"I'm a monster, right? A fucking dangerous killing machine, right?"

"Rin!" Yukio pulled him even closer, worry filling his voice. Something was wrong with his brother. "What are you talking about?!" Then something changed about Rin. His eyes were a even brighter blue than it usual, and had a unnatural glow to them. The older twin let out a soft chuckle, which grew into a crazed laugh.

"Rin?" Yukio said once again, filled with fear as he shook his brother's shoulders. Rin covered his face with one hand and continued laughing.

"Hello, my son."


	2. Chapter 2

**I hope you like Chapter 2! Also, thanks for the reviews guys!**

* * *

Yukio froze, as he heard a strange voice, not his brother's, coming abruptly from Rin's mouth. He stared at the brilliant, sapphire blue colored irises. Rin suddenly grasped his twin's arm and squeezed it.

"Something wrong with your hearing or what." Rin asked him threateningly, looking right into his eyes. Rin tightened his grip on Yukio's arm, which caused him wince from pain. "Will you be that courteous to give an reply when your father's asking, Yukio?" Hissed the boy.

" _Satan._ " Yukio growled, trying to escape and run away from him. But the iron grip of his brother denied any chance of escape. This only made him angrier.

"Such a beautiful encounter with my youngest son. You must have been envious that Rin's got the chance to meet me, right?" Satan started with a kind voice, but ended the reply teasingly, prevoking Yukio even further.

Yukio finally yanked free from "Rin's" grasp, and unsheathed his guns. He pointed the guns right at his brother's forehead. His trembling hands and whole body made Satan laugh with amusement.

"You think a small bullet could cause any pain to the King of Gehenna?" He asked. "And you're pointing your gun at your family..." Satan added, but he saw the bitter grimace on teenager's face and skipped to the other topic. "You see, I won't do any harm to you. I just want to fulfill my only wish. The reason behind your birth…" He explained putting his hand on his chest. A small smirk worked its way to his mouth as he continued.

"So you want to take Rin as you vessel?" Yukio asked and immediately became defensive. "Like hell you are!" He spat, glaring at his possessed brother. Then he touched the trigger of his gun and waited for any action from the other side.

"Oh, how I love those eyes..." The demon said sighing thoughtfully, meeting his gaze. Yukio was a bit disoriented, he didn't know what he meant by those words. When finally he remembered the fight in Kyoto, when his eyes changed into demonic ones. He touched the side of his face with his free hand, still pointing his gun at the target.

"Maybe I'll have some use of you. But from what I can see, you're still weak, my son." Informed Satan, getting up from the bed he had been seated on. "Unlike your dear _Nii-san_." Satan teased, and stretched before heading up to the boy.

"Oh, and please excuse me, but I'm going to have some fun now." He said as he was suddenly engulfed in blue flame. He licked his lips and smiled creepily. Yukio didn't have a chance to stop him, as the whole room became covered in Satan's flames. Everything was burning, some of the shelves felt to the ground making a horrible crashing noise. Yukio's sleeve caught the fire, but he ripped it off and ran outside.

He got minor burns on his hand and arm, but the pain wasn't easy to bear. His vision became blurred and he was hearing a strange noise. Yukio felt to the ground. He managed to stumble over to the bathroom and retrieve a small bottle, filled to the top with a green substance. He opened it and poured small drops onto the burns.

"Argh…" He winced from the pain, tightening his fists and looking up on the ceiling. He couldn't relax, he had to search for his brother before something happen. He gritted his teeth and tried to stand up, using his own full strength.

Satan/Rin was wandering around the yard, looking for someone to slaughter. He went on laughing in the most creepy way. He had hidden his blue flames, so as not to get caught before he would end the play. If he was lucky, when Rin woke up to find blood on his hands, it would finally break him! And when somethings broken, you can always mold it into something new.

Yukio left the corridor, which was burning with bright blue flames. He covered his mouth, so as not to get poisoned by any fumes that might be in the air. When he had burst out of the dorm, he bumped into Shiemi, who fell to the ground. She kept on caressing her bottom, which had been hurting, due to the impact of falling.

"Yuki-chan?" She asked, as she brushed her blonde bangs out from her vision. She then noticed that he was really terrified.

"Shiemi! You have to run from here, now!" He shouted, without giving her any explanation. He headed up to the main building, where lessons was taking place. He ran up higher, checking each corridor on each floor, searching for his brother.

He began to lose hope, but then suddenly he saw his older brother, kneeling and shivering.

" _Get the fuck away!_ " A terrible, frightened voice came out from the half-demon's mouth. Yukio shook from anger. _No_. Rin should never have to sound like that. Never. The older twin began to roll in pain on the floor, nearly choking himself as he grasped his throat.

 _"Why don't you try to act more like yourself, my son? Isn't it normal to seek blood, massacre? Just look, there is lots of people in the classroom…why don't you try and play around, just to relax?"_ A tempting voice of the ruler of Gehenna was echoing in his mind, without a single break. Rin began to scream, sobbing violently.

"SHUT UP! Shut up, shut up-"

 _"We both know you want to... **don't lie to me Rin.** "_

"STOP IT! Stop it, stop it, STOP IT!" Rin let out a wail, thrashing on the ground in pain.

Yukio ran up to him as fast as he could, trying to reassure his twin.

"Nii-san!" He yelled, grasping his brother's shoulders and shaking him strongly. He noticed he was crying. "Nii-san…" He repeated with softer voice. Soon Rin lost his consciousness, the pain, confusion, and voice in his head too much for a single soul to bear.

Both of them hadn't noticed that they made such a commotion, that everybody had come out of the classrooms.

* * *

 _ **"Why don't you just burn them? With your beautiful flames?"**_

Rin shook his head and looked around the place he was in. The cluttered room of his, but he wasn't alone. The sight of his own younger brother made him feel so relieved.

"What happened?" He asked, clearly not knowing what had just transpired. The question made the younger one a bit happier.

"Nothing. You just lost consciousness." Yukio replied in his common, rather harsh voice, but deep inside he was really relieved, that his brother couldn't recall anything from what had happened.

"What? I just simply…?"

"Nii-san. You're just unbelievable." He said laughing a bit and covering his mouth with a hand.

"Oi!"

 ** _"_ _Why are you running away, my dear son?"_**

* * *

 **Like? Hate? COMMENT!**


	3. Chapter 3

**A new chapter, yay! :D**

 **Thanks for the reviews!**

* * *

Everything seemed to be just as normal as it had been before. Rin couldn't recall a thing from what had happened.

He was just going to the cram school after a tiring day in the normal section. He strolled through the yard, that was covered in red, yellow- and brown-colored leaves, which lay spread over the ground, making it apear like a colorful carpet. Rin couldn't take his eyes away from them. A small, quite girl's voice broke him from his trance.

"Rin?" As he turned around, he saw the short, blond-haired girl, looking down to the ground, just like she was embarrassed. Then she suddenly lifted her head, nearly bumping into Rin's chin. "Everything's ok? I heard that you lost consciousness!" She uttered and then began to speak louder. Rin looked at her like he didn't know what she was talking about. Then, suddenly he remembered yesterday.

"Ah, that?" He started, scratching the back of his head and smiling. "That was just a minor thing." He informed her. Shiemi looked a bit happier and smiled as well.

"I'm relieved."

 _ **"Why don't you just burn her? Her skin, her bones…just everything?"**_

"Eh? You say something, Shiemi?" He looked straightly at her face, seeming a bit confused. He had heard a voice, but he couldn't figure out who's it was or even where it was coming from.

"No. Something wrong?" She replied and asked a little bit later, making a confused face as well.

* * *

Rin was sleeping in the middle of a lesson, as he had in habit since he had come to the cram school. Yukio was in lecturing the young Exwires, gazing straight at his brother and trying not to let his anger out.

Then he approached the desk, Rin had been sleeping on and hit with his fist, making a huge bang. Rin stood up due to the loud noise, and began to look around, so as to find the cause. Then he noticed his twin, looking unpleasantly at him with a sheet of paper in his right hand.

"If you hadn't scored such a marvelous grade, as for you, for the essay, I would have hit you in the head." He scolded, giving him the sheet.

" _Woah_!? Really? 70 points?!" He exclaimed, as he stared at the paper with amazement.

The older twin was just going to the dorm. It was quite dark and peaceful. Everything seemed normal. But something was really worrying Rin, as he was in the middle of the way. He felt as if someone was following him for few minutes. He couldn't get rid of the creepy feeling. He shivered.

"You're afraid?"

He turned around, but once again he couldn't recognize the specific, rather low voice. Then he saw someone, trying to hide from his sight, behind the wall of a building.

He grasped the sword hilt, ready to attack. When nothing had happened, he ran back to his place, where he felt the presence once more. But no one was there. He looked carefully around, but couldn't find anything either.

"Something's just wrong…"

* * *

"Sir Mephisto." Said Yukio, as he entered the room with sheets of paper in hand.

"Oh! Okumura-sensei!" Mephisto exclaimed rather enthusiastically, standing up and heading toward him. "I think, I know why you arrived at this place. Don't worry I have already taken preventative measures, if it goes to you brother." Said the demon king, waiting for his reaction, whatever it would be.

"What are you implying by that?" The young exorcist asked, as his facial expression changed into confusion. He tried to think of something that was different from before that possession of Rin, but he couldn't figure out.

"I'm saying that I have commanded some exorcist to look after Rin, so he won't harm anybody." He explained and stopped for a while, taking a small breath. "You know, people are the most precious things to me." He continued, turning around, so that he was looking right through the window, at the quite impressing landscape. "And you should not tell him about what happened, understood?"

"...Yes, sir."

* * *

 ** _"My beloved son, why won't you answer?!"_**

Rin once again woke up in similar situation. He was so disoriented, that he didn't even know where he was. He looked at the clock and decided to get up and head up to the bathroom, before it was occupied.

As he had finished all the preparations, he left the room and headed firstly to the cram school. They had to attend special class, right before the mid-year test.

When he passed through the door, right into the classroom, he noticed his friends sitting in his usual places. Yukio came to the room right after him and went to the desk up front.

"Everybody, from today on a new student will attend our cram school lessons. Take care of showing her around the place." Explained Yukio and pointed at the door, which a second later creaked. Beneath them a posture of girl appeared. She was tall, about 170 cm tall, had rather big, purple eyes with long eyelashes, which were covered by brown bangs. Too all that she was slender.

"Wanamiya Mirai." He continued, as she walked nearer. The boys were rather happy, just by looking at her appearance. With the exception of Rin, who was rather distracted, they couldn't take their eyes away.

"Take care of me!" She said giggling a little and sat in the first row, which Yukio had pointed at.

 _ **"I will be furious if you don't answer immediately, Rin."**_

* * *

 **Thx for all the support guys! I just got out of school Monday, so that means I'll be able to have more time to write for you guys! Oh, and I'm taking requests for Blue Exorcist Fics. I mainly do them around Rin, so feel free to submit a request! Suggestions for this fix are also welcome!**

 **Like? Hate? COMMENT!**


	4. Chapter 4

**Wow! Thanks for all the reviews guys! I'm sorry for any delay. And I'm thankful for all the atteintion the fanfic's getting!  
**

 **Enjoy! :o)**

* * *

 **"Don't make me repeat myself once again, you mischievous little brat."**

"Can I sit next to you?" Mirai asked politely, smiling happily, as she hovered over Rin. Her wisps of brown hair were pulled back, tucked neatly behind her ears.

"Yeah, sure." He responded, making a gesture, so as to invite her to the seat. She grinned at him and sat. She supported her head with her right hand and was looking at the black haired demon.

Realizing that, Rin tried not to move. He looked like he was extremely uptight. The boy shivered countless times, trying not to make such a show.

As the lesson had ended, Wanamiya came closer to the neighbour on her right, and tried to start a reasonable conversation.

"You're Rin, right? Okumura Rin?" She asked smiling once again. The whole smiling part made her look really nice and cheerful, but wasn't that a superficial individuality…

"Right, but how? Am I that famous?" He answered. _God, she's being kinda nosy._ Wanamiya's laughter took him away from his expectations. He made a sour face.

"I don't know if it's a hero's fame. But indeed, you're quite famous. _You're_ the son of Satan." She stated and waited for the response, but it sure had make her wait. Rin was confused to the extent, that he couldn't say a word. He always thought it was a top secret, known to a few exorcist, ranked higher than a normal Exwire.

"Why do you know that I'm his offspring?" He inquired, suddenly changing his attitude. He grabbed her slender arm and lifted it. She made a bored look.

"As I said earlier, you're famous within the whole school. And to all of that, I've been informed about every case before attending the class today." Mirai explained, making a long sigh and escaped from his touch. But something was telling Rin, that that wasn't the case. He somewhat knew, she was lying.

 **"Confused, aren't 'ya?"**

Rin suddenly shivered, as he heard a chilling voice, coming right from his head. He felt like someone was literally inside his head, making him feel insane, go berserk… He touched his head and started to press his hands on it as hard as he could, as if he could make everything return to normal state.

"Rin-kun?" Mirai uttered, as she looked straight down on him. The demon was still shaking and began to cry, without any reason.

"Rin?" Shiemi emerged from nowhere and kneeled to be on the same height as the black-haired classmate.

 **"So you've finally heard me properly? Splendid."**

"Get the fuck away from me!" Rin exclaimed, making Shiemi fall down from the shock. Everyone was looking at him now. The blond-haired girl stood up and ran to search for someone.

Rin was still situated on the floor, breathing heavily. He couldn't get rid of the chilling, terrifying voice. It was something that happened for the first time, not to this extent at least.

* * *

 ** _"Argh…!"_**

Yukio heard a terrible exclaim, coming out of nowhere. He tried to search for the person, but he couldn't find anyone, that could be accused of making the action.

Deep inside his head, a nearly inaudible voice, was telling him, that something bad was either about to happen or has already happened. He stood up, making a loud rattle. After thinking about it for a bit, he realized, that something must have happened to his older twin brother.

He ran as fast as he could, and made it to the cram school's classroom.

"Nii-san!" He shouted in a panicked voice, trying to figure out what was happening. As he walked in, he bumped into Shiemi, who had been going to exit the room, before she landed on the floor for the second time today.

"Yuki-chan!"

"Moriyama, what's going on? Where's Rin?" He asked, spinning around.

"There!" She said, as she indicated Rin, who was laying behind the desk. Yukio ran up and tried to shake his shoulder.

 **"Go away!"** He shouted, his voice resounding throughout the room.

"Nii-san! What's up with you?"

Rin exhaled heavily, still shaking. His vision was becoming more blurred with every second.

"This voice…" He uttered, sobbing like he was in a pain. "He…"

"Mirai." He rather soft voice responded. The voice belonged to Mephisto, who at that moment was sitting on his chair, looking on the landscape right behind the window.

"Yes, sir." She answered, as she emerged from darkness.

"You have to make sure, that the little brother of my will become more aware of his individuality." He stated, spinning on the chair, so as to look straight at the girl.

"Yes, sir." She responded automatically. Mephisto looked at her once again and frowned.

"Are you sure you won't object?" He asked, waiting for a reasonable response. In exchange he got a rather evil laughter, coming out of her mouth.

"I don't care."

* * *

 **I'm sorry if it's confusing. So Mirai is working for Mephisto to keep a eye on Rin and his mental health. She's not an OC, just a filler character. Also, I've been having a bit of a writers block lately, so it would really be appreciated for some suggestions or help!**

 **Like? Hate? COMMENT!**


	5. AUTHORS NOTE

**I apologize for the lack in updates recently, but it seems I have a writers block. *dramatic music plays***  
 **Me: *glares at them***

 **...**

 **So, I am now taking requests from you dear readers! Because right now my inspiration tank is fucking empty. Tell me in the comments on what you want to happen in the story, and I'll take the best suggestions and use them for the upcoming chapters. I will also credit the person who came up with the idea in the beginning of the chapter. Although there are a few ground rules before you all start piling up requests.**

 ****

 **The first is that I will not do any yaoi. Minor shipping, maybe, but no yaoi. Save that for other Fics. The next is that I still want Rin to be the main character. And thirdly, NO OC'S. Yes, I know you all think that I added a OC, but the only OC I have ever created is the one who's a version of myself. So Mirai is NOT a OC, just a filler character.**

 ****

 **Please send in requests though. All you fanfic writers know how shitty it is to have a writer's block, so some fresh ideas are really needed right now. Thank you, and I'll get to writing the story as soon as possible. :o)**


	6. School stuff(Not a new chapter, sorry)

**Yes, I know what you're thinking: Another authors note!? Seriously? Where's the stories?! And yes, I understand. But I'm trying my best with the story, and I just wanted you to know that I have school coming up, actually extremely soon. I know many of you know how hard it is to write and do school stuff at the same time, so I hope you understand. Plus, I'm going into eighth grade this year, (Yes, eighth.) so that means algebra shit. But I promise, on my honor as a writer, and a anime fan, that I WILL do everything I can in my free time to continue with this fanfic. Plus, I've already got the first part of the next chapter written, so I hope you guys can wait just a little more, because I'm almost done with it~**

 **please forgive me, though...**


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